Systems and methods for using a transformer to achieve uniformity in processing a substrate

Abstract

Systems and methods for using a transformer to achieve uniformity in processing a substrate are described. One of the systems includes a primary winding having a first end and a second end. The first end is coupled to an output of an impedance matching circuit and the second end is coupled to a capacitor. The system further includes a secondary winding associated with the primary winding and coupled to a first end and a second end of a transformer coupled plasma (TCP) coil of a plasma chamber. The primary winding receives a modified radio frequency (RF) signal from the impedance matching circuit to generate a magnetic flux to induce a voltage in the secondary winding. An RF signal generated by the voltage is transferred from the secondary winding to the TCP coil.

1 . A transformer apparatus, comprising:
 a primary winding having a first end and a second end, wherein the first end is coupled to an output of an impedance matching circuit and the second end is coupled to a capacitor;   a secondary winding associated with the primary winding and coupled to a first end and a second end of a transformer coupled plasma (TCP) coil of a plasma chamber,   wherein the primary winding is configured to receive a modified radio frequency (RF) signal from the impedance matching circuit to generate a magnetic flux to induce a voltage in the secondary winding, wherein an RF signal generated by the voltage is transferred from the secondary winding to the TCP coil.   
     
     
         2 . The transformer apparatus of  claim 1 , wherein the TCP coil is in series with the secondary winding. 
     
     
         3 . The transformer apparatus of  claim 1 , further comprising:
 an additional primary winding having a first end and a second end, wherein the first end of the additional primary winding is coupled to the output of the impedance matching circuit and the second end of the additional primary winding is coupled to an additional capacitor;   an additional secondary winding associated with the additional primary winding and coupled to a first end and a second end of an additional TCP coil of the plasma chamber,   wherein the additional primary winding is configured to receive a modified RF signal from the impedance matching circuit to generate a magnetic flux to induce a voltage in the additional secondary winding, wherein an RF signal generated by the voltage induced in the additional secondary winding is transferred from the additional secondary winding to the additional TCP coil.   
     
     
         4 . The transformer apparatus of  claim 1 , wherein the capacitor is coupled to a ground connection. 
     
     
         5 . The transformer apparatus of  claim 1 , wherein the secondary winding is twisted with the primary winding to be associated with the primary winding. 
     
     
         6 . The transformer apparatus of  claim 1 , wherein the secondary winding is rolled in an interspersed manner with the primary winding to be associated with the primary winding. 
     
     
         7 . The transformer apparatus of  claim 1 , wherein the capacitor is a variable capacitor or a fixed capacitor. 
     
     
         8 . The transformer apparatus of  claim 1 , wherein the capacitor is a variable capacitor that is coupled to a motor to change a capacitance of the variable capacitor. 
     
     
         9 . The transformer apparatus of  claim 1 , wherein multiple taps are provided on the secondary winding to change the voltage that is applied by the secondary winding to the TCP coil. 
     
     
         10 . The transformer apparatus of  claim 1 , wherein the first end of the primary winding is coupled via another capacitor to the impedance matching circuit, wherein the other capacitor is a fixed capacitor or a variable capacitor. 
     
     
         11 . A transformer apparatus, comprising:
 a primary winding having a first end and a second end, wherein the first end is coupled to an output of an impedance matching circuit and the second end is coupled to a capacitor;   a first secondary winding associated with the primary winding and coupled to a first end and a second end of a first transformer coupled plasma (TCP) coil of a plasma chamber,   wherein the primary winding is configured to receive a modified radio frequency (RF) signal from the impedance matching circuit to generate a magnetic flux to induce a voltage in the first secondary winding, wherein an RF signal generated by the voltage induced in the first secondary winding is transferred via the first secondary winding to the first TCP coil,   a second secondary winding associated with the primary winding and coupled to a first end and a second end of a second TCP coil of a plasma chamber,   wherein the magnetic field is configured to induce a voltage in the second secondary winding, wherein an RF signal generated by the voltage induced in the second secondary winding is transferred from the second secondary winding to the second TCP coil.   
     
     
         12 . The transformer apparatus of  claim 11 , wherein the first TCP coil is in series with the first secondary winding and the second TCP coil is in series with the second secondary winding. 
     
     
         13 . The transformer apparatus of  claim 11 , further comprising:
 an additional primary winding having a first end and a second end, wherein the first end of the additional primary winding is coupled to the output of the impedance matching circuit and the second end of the additional primary winding is coupled to an additional capacitor;   an additional first secondary winding associated with the additional primary winding and coupled to a first end and a second end of a third TCP coil of the plasma chamber,   wherein the additional primary winding is configured to receive a modified RF signal from the impedance matching circuit to generate a magnetic flux to induce a voltage in the additional first secondary winding, wherein an RF signal generated by the voltage induced in the additional first secondary winding is transferred from the additional first secondary winding to the third TCP coil;   an additional second secondary winding associated with the additional primary winding and coupled to a first end and a second end of a fourth TCP coil of the plasma chamber,   wherein the magnetic flux generated by the additional primary winding induces a voltage in the additional second secondary winding, wherein an RF signal generated by the voltage induced in the additional second secondary winding is transferred from the additional second secondary winding to the fourth TCP coil.   
     
     
         14 . The transformer apparatus of  claim 11 , wherein the capacitor is coupled to a ground connection. 
     
     
         15 . The transformer apparatus of  claim 11 , wherein the capacitor is a variable capacitor or a fixed capacitor, wherein the variable capacitor is coupled to a motor to change a capacitance of the variable capacitor. 
     
     
         16 . The transformer apparatus of  claim 11 , wherein the first secondary winding is twisted around the primary winding to be associated with the primary winding and the second secondary winding is twisted around the primary winding to be associated with the primary winding. 
     
     
         17 . The transformer apparatus of  claim 11 , wherein the first secondary winding is rolled in an interspersed manner with the primary winding to be associated with the primary winding and the second secondary winding is rolled in an interspersed manner with the primary winding to be associated with the primary winding. 
     
     
         18 . The transformer apparatus of  claim 11 , wherein the first end of the primary winding is coupled via another capacitor to the impedance matching circuit, wherein the other capacitor is a fixed capacitor or a variable capacitor. 
     
     
         19 . A method comprising:
 receiving, by a primary winding of a transformer, a modified radio frequency (RF) signal from an output of an impedance matching circuit, wherein the primary winding is coupled to a capacitor;   upon receiving the modified RF signal, generating, by the primary winding, a magnetic flux to induce a voltage across a secondary winding of the transformer; and   transferring an RF signal generated by the voltage from the secondary winding to a transformer coupled plasma (TCP) coil of a plasma chamber.   
     
     
         20 . The method of  claim 19 , wherein the TCP coil is in series with the secondary winding.